1. Field of the Invention
The present invention relates to a production system for printed wiring boards.
2. Description of the Related Art
Conventionally, printed wiring boards have been produced generally in the following manner. A substrate material in which a conductive film is formed on the surface of an insulated plate thereof (called “raw material”) is prepared. A circuit pattern, solder resist and the like are formed on the raw material. After that, the excess portion of the raw material is cut off and removed and then the final product, printed wiring boards, is obtained.
The size and shape of the raw material is determined to be a specific size and a specific shape, and it is known as a “predetermined manufacturing block.” A manufacturer of printed wiring boards determines the layout for the final product of printed wiring boards on that predetermined manufacturing block. This work is called “panelizing.”
During panelizing, according to the dimensions of the predetermined manufacturing block, the positions of a circuit pattern, solder resist and the like to be formed on the material and the cutting lines on the material for the final product and the like are determined.
The result of the panelizing is reflected on a group of printed wiring boards. According to the panelizing result, for example, an art work film for forming etching resist and solder resist for forming a circuit pattern is created and then, the setting for forming the circuit or solder resist is carried out in respective units for use in a circuit forming process and a solder resist forming process by using the created art work film. Further, setting for an operation based on the result of the panelizing is carried out in a unit for drilling the raw material, a punching unit, and a cutting unit. If an instruction for manufacturing a printed wiring board (the instruction being called a “charge”) is given to a group of manufacturing units for use in the manufacturing process, the respective units execute manufacturing processes according to the result of the panelizing.
If a large number of printed wiring boards are intended to be produced, a plurality of the printed wiring boards of the same kind are panelized in the predetermined manufacturing block in order to reduce the unused remaining portion of the raw material and to obtain as large a number of the printed wiring boards as possible from the predetermined manufacturing block (for panelizing for the same kind of printed wiring boards).
As a special case, if multiple kinds of the printed wiring boards are used as parts of the same machine (for example, it is intended to manufacture multiple kinds of printed wiring boards for a TV and a portable telephone), a predetermined manufacturing block is panelized for each printed wiring board (panelizing for different shapes) in order to obtain multiple kinds of the printed wiring boards from the same predetermined manufacturing block.
According to the above-described conventional technology, an art work film is created corresponding to the result of the panelizing. The art work film is expensive and requires much attention for storage. For this reason, the content of the panelizing in the predetermined manufacturing block has never been changed according to the manufacturing request for the printed wiring board.
Thus, if panelizing for the same shape is carried out in the predetermined manufacturing block, an art work film corresponding to that panelizing is created, and regardless of the quantity of boards requested to be manufactured, just printed wiring boards of a multiple of a number of those panelized are manufactured. For this reason, if the manufacturing quantity of the printed wiring boards cannot be divided evenly by the number of boards panelized in the predetermined manufacturing block according to the same shape, excessive printed wiring boards (called “incidental products”) are generated. The generation of such incidental products is not favorable from the viewpoint of production costs and other costs for storage, for example.
In recent years, with the diversification of users, the kinds of the printed wiring boards have been increasing and the life cycles of the printed wiring boards have reduced rapidly. Thus, the production of printed wiring boards has been changing from the conventional production of few kinds in large quantity of each to the production of many kinds in small quantities of each. Accompanied by this trend, ultra-minority products, which are requested to be manufactured in extremely small quantities (1 or 2), have been generated. If, to manufacture this ultra-minority product, a single ultra-minority product is panelized in a predetermined manufacturing block, the amount of material which is removed and thrown away by cutting out that product increases, and this is not favorable from the viewpoint of production costs.